This proposal describes additional studies to be performed on the anti-tumor properties of lymphokines found in the supernatant of cultured long term human lymphoblasts. Studies performed to date include: preliminary studies in patients with intralesional injection of concentrated preparations which have induced regressions of metastatic cancer lesions, studies which show significant prolongation of survival in mice bearing transplanted subcutaneous lymphomas and melanoma, in preclinical, acute toxicity and sterility, and biochemical purification of 3H labelled starting material. Our tentative findings indicate that the anti-tumor effective lymphokines range in molecular weight from 15-45,000 on SDS gels and are most likely glycoproteins. They induce an inflammatory reaction containing large numbers of activated macrophages (histiocytes) within 48 hours of injection and effect tumor regression by inducing macrophage infiltration and activation. Additional studies described herein consists of scaled-up production and purification of supernatants, further studies of mouse tumor models, and acquisition of chronic toxicity data and initiation of a Phase I study in tumor patients. The goal of the program is a complete structural characterization of the active moieties promoting tumor regression.